Low-threshold colloidal quantum dot polariton lasing via a strong coupling microcavity at room temperature

Colloidal quantum dots (CQDs) are excellent optical gain media that can be synthesized through low-cost and easily controlled techniques, holding significant promise for applications in semiconductor laser devices. In this study, we demonstrated polariton coherent lasing based on a CdSe-based CQD microcavity device at room-temperature (RT) for the first time. The dispersion behaviors of CQD polaritons with different excitation powers were comprehensively analyzed using angle-resolved spectroscopy techniques. The lasing behavior at a threshold of 49 μJ cm^-2 and the energy blue-shift were well aligned with the typical characteristics of robust polariton Bose-Einstein condensation (BEC) theory. Moreover, the linewidth of the polariton lasing peak was narrowed down to 0.65 nm at 1.13P_th. Additionally, the polarization characteristics and temporal dynamics of the CQD-microcavity polariton lasing were discussed. It was noted that the lifetime of CQD polaritons during condensation was reduced from 1.3 ns (0.8P_th) to 68 ps (1.6P_th). Our results provide valuable insights into the strong coupling, low-threshold CQD microcavity laser at RT and promote its further practical application.